In a reciprocating compressor driven by a linear motor, the gas suction and gas compression operations are carried out with the reciprocating axial movements of the piston in the interior of a cylinder closed by a head and, in some constructions, mounted in the interior of a hermetic shell of the compressor. The piston is driven by a motor unit of the compressor.
Pistons for a refrigeration compressor generally present a monolithic construction, defining, in a single piece, the formation of a head portion and a skirt portion, said piston construction being obtained, for example, by machining a metallic blank, usually made of steel. This manufacturing process is expensive and presents a high material waste.
There are also known other processes for obtaining pistons in a single piece for refrigeration compressors, such as cold shaping, stamping, etc. However, said processes, besides having a still high cost, present pieces with a high degree of dimensional uncertainty, which affects the actuation of the piston in the compressor.
These disadvantages are still greater in the constructions in which the suction is provided through the piston body.
Besides the above disadvantages, the monolithic constructions for the piston of a refrigeration compressor do not result in pistons presenting low material and production costs, low weight, good resistance, low porosity, low friction coefficient, etc., which characteristics are mainly relevant in long pistons and, more particularly, in pistons which operate in a compressor without oil lubrication or also in a gas bearing compressor.